Organic/carbon nanotubes hybrid thin films for chemical detection.

Metallophthalocyanines (MPcs) are classified as an important class of conjugated materials and they possess several advantages attributed to their unique chemical structure. Carbon nanotubes (CNT), on the other hand, are known to enhance the properties of nano-composites in the conjugated molecules, due to their one dimensional electronic skeleton, high surface area and high aspect ratio. In this thesis, work has been carried out on the investigation of different substituted metal-phthalocyanines with the aim of developing novel hybrid film structures which incorporates these phthalocyanines and single-walled carbon nanotubes (SWCNT) for chemical detection applications. Octa-substituted copper phthalocyanines (CuPcR[8]) have been characterised using UV-visible absorption spectroscopy. Obtained spectra have yielded an evidence of a thermally induced molecular reorganization in the films. Influence of the nature of substituents in the phthalocyanine molecule on the thin films conductivity was also investigated. Octa-substituted lead (II) phthalocyanines (PbPcR[8]) have also been characterized using UV-visible spectroscopy. Sandwich structures of ITO/PbPcR[8]/In were prepared to investigate the electronic conduction in PbPcR[8]. The variation in the J(V) behavior of the films as a result of heat treatment is expected to be caused by changes in the alignment inside the columnar stacking of the molecules of the films. Thin films of non-covalently hybridised SWCNT and tetra-substituted copper phthalocyanine (CuPcR[4]) molecules have been produced. FTIR, DC conductivity, SEM and AFM results have revealed the [mathematical equation]; interaction between SWCNTs and CuPCR[4] molecules and shown that films obtained from the acid-treated SWCNTs/CuPcR[4] hybrids demonstrated more homogenous surface. Thin films of pristine CuPCR[4] and CuPcR[4]/S WCNT were prepared by spin coating onto gold-coated glass slides and applied as active layers for the detection of benzo[a]pyrene, pentachlorophenol (PCP), 2-chlorophenol, diuron and simazine in water as well as amines vapours in ambient air utilizing total internal reflection spectroscopic ellipsometry (TIRE) as an optical detection method. Different concentrations of pesticides in water ranging from 1 to 25 mug/L have been examined. It was revealed that the shifts in [mathematical equation] spectra of CuPcR[4]SWCNT films were evidently larger than those produced by the pristine CuPcR[4] films, indicating largely improved films' sensitivity of the hybrid films. Adsorption of amines onto films' surfaces has been realised by monitoring changes in the phase shift [mathematical equation] of TIRE. Methylamine has shown higher sensitivity and lower response time among the studied amines. For all amines vapours, the sensitivity of SWCNT/CuPcR[4] hybrid films was higher than the sensitivity of pristine Cu[1]PCR[4] films. Further work has been carried out on hybrids of SWCNT with zinc phthalocyanines (ZnPc). Thin films of pristine SWCNT and SWCNT/ZnPc hybrids were prepared by drop casting onto interdigitated electrodes and applied as active layers to detect ammonia vapor by measuring electrical resistance changes. Influence of pyrene substituent in the phthalocyanine ring on the hybrid formation and their sensor response has also been verified

Tetrasubstituted copper phthalocyanines : correlation between liquid crystalline properties, films alignment and sensing propertie

Copper phthalocyanines (CuPc) containing alkylthio (-S(CH2)nCH3, n=7 and 15), alkyloxy- (-O(CH2)nCH3, n=7 and 15) and polyoxo (-O(CH2CH2O)3CH3 and -S(CH2CH2O)3CH3) substituents were synthesized and investigated to reveal the effects of substituents type (alkylthio, alkyloxy and polyoxo) and the type of the connecting heteroatom (oxygen or sulphur) on the mesogenic properties, films alignment and sensing behaviour. The liquid crystalline properties of these phthalocyanines were investigated by differential scanning calorimetry, polarizing optical microscopy and X-ray diffraction techniques. The structure and morphology of spun thin films of copper phthalocyanine derivatives were studied by the UV-Vis and Raman spectroscopies as well atomic force microscopy. The sensing properties of CuPc films were studied by the measurement of conductivity change upon interaction with ammonia in the range 10-50 ppm. All investigated films of CuPc derivatives display thermotropic columnar mesomorphism. It was shown that the films with polyoxo- (-O(CH2CH2O)3CH3 and -S(CH2CH2O)3CH3) substituents as well as with alkylthio -S(CH2)nCH3 (n=7) substituents, which are liquid crystalline at room temperature, form ordered films with a random planar alignment of columns. Their films exhibit the better sensor performance with the maximal sensor response for the films of CuPc containing (-S(CH2CH2O)3CH3) substituents

High performance ternary solar cells based on P3HT:PCBM and ZnPc-hybrids

Single walled carbon nanotubes (SWCNTs) and reduced graphene oxide (rGO) covalently and non-covalently functionalised by zinc phthalocyanine (ZnPc) were added to P3HT:PCBM blend in order to investigate the effects of these hybrid materials on P3HT:PCBM organic solar cell performance. Adding a small amount of these hybrids to P3HT:PCBM blend does not significantly alter the absorption spectra of the latter nor its structure. ZnPc–rGO and ZnPc–SWCNT hybrid features have appeared on the P3HT:PCBM surface morphology as verified by SEM and AFM images. However these hybrid materials have caused significant effects on the electrical properties of the studied blends. An increase of about two orders of magnitudes has been observed in the electrical conductivity. Space charge limited conduction theory was employed to investigate the charge carriers' mobility whereas a thermionic emission model was used to evaluate the recombination rate based on an estimated diode ideality factor. Solar cell devices based on P3HT:PCBM:ZnPc–SWCNTs-co bonded have demonstrated best device performance with PCE of 5.3%, Jsc of 12.6 mA cm−2, Voc of 0.62 V and FF of 68%. A reference device based on bare P3HT:PCBM blend has exhibited PCE of just under 3.5%, Jsc of 9.3 mA cm−2, Voc of 0.62 V and FF of 60%

Study of the sensor response of spun metal phthalocyanine films to volatile organic vapors using surface plasmon resonance

tIn this work, thin films of chloroaluminium phthalocyanine (ClAlPc), fluoroaluminium phthalocyanine(FAlPc) and fluorochromium phthalocyanine (FCrPc), which are insoluble in conventional solvents, weredeposited by spin coating of their solutions in trifluoroacetic acid. The sensing response of these filmsversus acetic acid, three alcohols (methanol, ethanol, butanol) and three amines (methylamine, dimethy-lamine, trimethylamine) have been investigated using surface plasmon resonance as the sensing method.It has been shown that the sensor response of the investigated films decreases in the following order:acetic acid > alcohols > amines. The optical changes as monitored by SPR method have been used in con-junction with Fick’s second law of diffusion to determine the diffusion coefficients of analyte vapor duringthe films’ swelling process. The obtained results showed that the diffusion coefficients and the swellingcharacteristics of the films are dependent on the functional group of the phthalocyanine molecule andthe molecular size of the analyte

Genotypic assay to determine some virulence factors of Uropathogenic E. coli (UPEC) isolates

A total of 179 urine samples were collected from patients suffering from urinary tract infections were admitted and visit Al-Hilla General Teaching Hospital in Al-Hilla City, during a period from April 2021 to December 2021, from both sex (male and female). Out of 179,123 (68.7%) were positive culture, whereas 56 (31.3%) samples showed no bacterial growth, To confirm the identification of E. coli by use selective media (EMB agar medium, biochemical tests, automated Vitek 2 system and 16s RNA specific primer by the presence of (1492 bp) compared with allelic ladder, it was found that, E. coli were deliberated the main an etiological causes UTI to other types bacteria which constitute 56/123 (45.5%), [45/56 (80.4%) from female and 11/56 (19.6%) from male], while 67/123 (54.4%) were related to other types of bacteria. Molecular detection of some virulence factors genes were studied, out of 56 E. coli isolates, hlyA gene was detected in 21/56 (37.5%) isolates by the presence of (1177 bp) and sat gene was detected in 35/56 (62.5%) isolates by the presence of (410 bp) compared with allelic ladder

Genotypic Assay to Determine Some Virulence Factors of Uropathogenic E. Coli (UPEC) Isolates

A total of 179 urine samples were collected from patients suffering from urinary tract infections were admitted and visit Al-Hilla General Teaching Hospital in Al-Hilla City, during a period from April 2021 to December 2021, from both sex (male and female). Out of 179,123 (68.7%) were positive culture, whereas 56 (31.3%) samples showed no bacterial growth, To confirm the identification of E. coli by use selective media (EMB agar medium, biochemical tests, automated Vitek 2 system and 16s RNA specific primer by the presence of (1492 bp) compared with allelic ladder, it was found that, E. coli were deliberated the main an etiological causes UTI to other types bacteria which constitute 56/123 (45.5%), [45/56 (80.4%) from female and 11/56 (19.6%) from male], while 67/123 (54.4%) were related to other types of bacteria. Molecular detection of some virulence factors genes were studied, out of 56 E. coli isolates, hlyA gene was detected in 21/56 (37.5%) isolates by the presence of (1177 bp) and sat gene was detected in 35/56 (62.5%) isolates by the presence of (410 bp) compared with allelic ladder

Surface interaction of copper phthalocyanine modified single walled carbon nanotubes with pesticides

Hybrid materials were produced by mixing tetrakis(hexadecylthio) substituted copper(II) phthalocyanine (CuPcR4) with acidified single-walled carbon nanotubes (SWCNTs) and they were characterised by UV-vis absorption spectroscopy, scanning electron microscopy and atomic force microscopy. Thin films of pristine CuPcR4 and CuPcR4/SWCNT were prepared by spin coating onto gold-coated glass slides and applied as active layers to detect pentachlorophenol (PCP), 2-chlorophenol, diuron and simazine in water utilising total internal reflection ellipsometry (TIRE) as an optical detection method. Different concentrations of pesticides in water ranging from 1 to 25 μg/L have been examined in the current work. It is revealed that the shifts in Δ(λ) spectra of CuPcR4/SWCNT films were evidently larger than those produced by the pristine CuPcR4 films, indicating largely improved films' sensitivity of the hybrid films. The sensitivity has been calculated according to the phase shift in the Δ(λ) spectra. The higher sensitivity was found to be 0.00396/(μg/L) towards PCP in case of CuPcR4/SWCNT sensor. The lower detection limit has been calculated to be 840 ng/L

Effect of pyrene substitution on the formation and sensor properties of phthalocyanine-single walled carbon nanotube hybrids

The hybrids of single walled carbon nanotubes (SWCNTs) with symmetrically octasubstituted zinc phthalocyanine (2) bearing eight polyoxyethylene groups and asymmetrically substituted zinc phthalocyanine (1) bearing one pyrene and six polyoxyethylene groups as side chains have been prepared and characterized by Raman and fluorescence emission spectroscopies, scanning electron and transmission electron (SEM and TEM) microscopies, and thermogravimetric analysis. The pyrene group was chosen to enhance the interaction of phthalocyanine molecules with SWCNTs. Thin films of pristine SWCNTs and SWCNT/ZnPc hybrids were prepared by drop casting onto interdigitated electrodes and employed as active layers to detect ammonia vapour (1-200 ppm) by measuring electrical resistance changes. A comparative analysis of sensors' response of pristine SWCNTs and SWCNT/ZnPc hybrid films to ammonia vapour was carried out to demonstrate the synergic effect between SWCNTs and ZnPc derivatives. Influence of pyrene substituent in the phthalocyanine ring on the hybrid formation and their sensor response has also been discussed